Osteoblasts are known to be large cells in control of the synthesis and mineralization of bone formation and the subsequent remodeling of the same. The process of bone formation from osteoblasts is known as osteogenesis and involves three basic steps: (a) Synthesis of extracellular organic matrix (osteoid), (b) Matrix mineralization leading to the formation of bone, (c) Remodeling of bone by the process of resorption and reformation. Bone remodeling is a continuing process of synthesis and destruction that gives bone its mature structure and maintains the normal structure of bone. Now, destruction, or resorption of bone occurs by virtue of large cells called osteoclasts.
The conventional methods used for replacement of defect bones in bone associated diseases or during circumstances of new bone formation due to breakage or injury, are numerous. Depending on the case, certain scenarios can prove to be very challenging, especially the realignment of the bone.
Autologous bone graft of various types is available, which provide good mechanical and biological properties but factors like donor site morbidity, molding challenges, limited operative time for graft harvest and the limited volume in term of quantity available is a great concern. Again, allograft, which involves the transplant of a tissue, is one where the donor is of a different genetic makeup. Although allograft mitigates a few issues associated with autologous bone graft as there is no donor site morbidity and there is no limitation with respect to the quantity, few other problems are involved, which could be the sterilization process which weakens the bone rejection reactions due to a different genetic make-up or the graft may transmit infections such as hepatitis and HIV/AIDS.
Bone generation by virtue of growth factors such as BMPs (Bone morphogenic proteins) which is yet another method wherein the quantitative replacement of defective bone is considerably less to provide predictable results.
Therefore, the above-mentioned problems associated with the existing methods for replacement of defect bones need to be alleviated.